KR102479934B1 - Novel Polyester fiber for binder with Advanced Adhesive Strength - Google Patents

Abstract

The present invention is a polyester fiber for a binder formed of a sheath portion and a core portion, wherein the core portion is formed of a general polyester resin, and the sheath portion contains terephthalic acid or an ester-forming derivative thereof and oxalic acid as an acid component, and a diol component It is formed of a polyester resin for a binder containing ethylene glycol, and oxalic acid of the polyester resin for a binder contains 30 to 60 mol% of the acid component.

Description

Novel Polyester fiber for binder with Advanced Adhesive Strength}

The present invention relates to a novel polyester fiber for a binder, which is formed of a new and novel polyester resin for a binder using a copolymer not used in a conventional polyester resin for a binder. It is about.

Polyester, as an eco-friendly material, has excellent mechanical properties and excellent heat resistance and chemical resistance, so it can be used in various fields requiring light weight and high physical properties. Recently, the role of polyester fibers represented by polyethylene terephthalate (PET) in the field of fibers such as nonwoven fabrics is increasing. Specifically, an example is the increasing demand for heat-adhesive fibers that use polyester resin as an adhesive component and can be used for clothing adhesive cores or automobile interior materials.

Accordingly, efforts to improve the physical properties of polyester fibers and expand their utilization are being conducted from various angles, and as part of these efforts, technology to control temperatures such as softening point or glass transition temperature by modifying the structure of polyester resins are being studied. For example, a technique for controlling the melting point or glass transition temperature of a polyester resin by copolymerizing a dicarboxylic acid such as terephthalic acid, isophthalic acid, adipic acid, or sebacic acid with a diol compound such as ethylene glycol or neopentyl glycol has been developed. there is.

In particular, when manufacturing a web or sheet of nonwoven fabric with polyester fiber, the heat-sealing binder polyester fiber used to bond filaments or short fibers has a heat-sealing processing temperature of 120 to 200 ° C, which is typical for polyethylene tere It should have a lower melting or softening point compared to phthalate fibers.

For this purpose, in synthesizing a polyester resin, it is a representative method to copolymerize with terephthalic acid using isophthalic acid as a copolymerization component. At this time, isophthalic acid is added in an amount of 20 to 45 mol% based on ester mole, and the polyester resin synthesized in this way is amorphous. It has a molecular structure of the form and shows a final melting point in the range of 145 ~ 180 ℃ can be used as a polyester fiber for binder.

However, when synthesizing a polyester resin for a binder using isophthalic acid, a cyclic compound having a degree of polymerization of 2 to 3 is formed. This cyclic compound has the disadvantage of shortening the pack exchange cycle by acting as a foreign substance during spinning because it does not melt at the polyester spinning temperature with a melting point of about 325 ° C. In addition, the price of isophthalic acid is also high, so the cost increases. becomes a factor of

US Patent No. 4,129,675 discloses a low-melting polyester binder containing terephthalic acid and isophthalic acid as main components, but this is uneconomical because it requires a temperature of 200° C. or higher during thermal bonding.

U.S. Patent No. 4,166,896 discloses a method for preparing unsaturated polyester by copolymerizing unsaturated dicarboxylic acid with a low molecular weight material obtained by depolymerizing polyester. There are disadvantages of excessively high melting point and high crystallinity.

US Patent No. 4,065,439 discloses a low-melting polyester obtained by using terephthalic acid/isophthalic acid/adipic acid (or sebacic acid) and ethylene glycol/neopentyl glycol, but the melting point of the binder is 45° C. to 60° C. It is too low to be used as an interlining for clothing, and its shape stability under high temperature conditions is also weak.

Meanwhile, Korean Patent Laid-open Publication No. 2001-11548 discloses poly, which has excellent adhesion to polyester and does not cause yellowing after adhesion, by condensation polymerization of dicarboxylic acid components of terephthalic acid and phthalic anhydride and diol components of ethylene glycol and diethylene glycol. Although a binder for ester-based fibers is provided, since the binder directly uses phthalic anhydride, the reaction mechanism is complicated, and accordingly, the condensation polymerization temperature must be lowered to prevent the color of the copolymerized polyester from being poor.

In addition, in Korean Patent Registration No. 1684234, terephthalic acid is used as an acid component and 2-methyl-1,3-propanediol and ethylene glycol are used as main components in the diol component, so that the softening point is in the range of 110 to 130 ° C. It is disclosed that it can be used for polyester fibers.

As described above, polyester resins for binders have been developed with various chemical compositions using various copolymer compounds, but polyester resins for binders that are actually used are limited, and compounds used for copolymerization of polyester resins for binders If the supply is not smooth due to various factors such as difficulty in supply and demand, rapid increase in price, product production may be disrupted.

Therefore, various products through diversification of copolymer compounds used in polyester resins for binders are required, and polyester resins for binders having binder properties similar to or superior to commercialized polyester resins for binders and polyesters for binders using the same There is a need for the development of textiles.

The present invention was invented to solve the problems of the prior art as described above, and uses oxalic acid, which has not been used in the past, as a copolymer compound for binders having similar or superior binder properties to conventional polyester resins for binders. An object of the present invention is to provide a polyester fiber for a binder containing a polyester resin.

In addition, it is an object of the present invention to provide polyester fibers for binders for various purposes through the content of oxalic acid in the polyester resin for binders.

The present invention is a polyester fiber for a binder formed of a sheath portion and a core portion, wherein the core portion is formed of a general polyester resin, and the sheath portion contains terephthalic acid or an ester-forming derivative thereof and oxalic acid as an acid component, and a diol component It is formed of a polyester resin for a binder containing ethylene glycol, and oxalic acid of the polyester resin for a binder provides a polyester fiber for a binder, characterized in that it contains 30 to 60 mol% of the acid component.

In addition, oxalic acid of the polyester resin for binder provides a polyester fiber for binder, characterized in that it contains 30 to 50 mol% of the acid component.

In addition, the polyester resin for the binder provides a polyester fiber for the binder, characterized in that the softening temperature is 100 ℃ ~ 150 ℃.

In addition, the polyester resin for the binder provides a polyester fiber for the binder, characterized in that the glass transition temperature is 60 ℃ to 90 ℃.

In addition, it provides a nonwoven fabric comprising the polyester fiber for the binder.

As described above, the novel polyester fiber for a binder according to the present invention uses oxalic acid, which was not used in the conventional polyester resin for a binder, as a copolymer compound, and has similar or superior binder properties to the conventional polyester resin for a binder. It has an effect of providing a polyester fiber for a binder including a polyester resin for a binder.

By adjusting the content of oxalic acid used as an acid component of the polyester resin for binder, it is possible to provide polyester fibers for binders for various purposes.

Hereinafter, a preferred embodiment of the present invention will be described in detail. First of all, in describing the present invention, detailed descriptions of related known functions or configurations are omitted in order not to obscure the gist of the present invention.

As used herein, the terms 'about', 'substantially', and the like are used in a sense at or approximating that number when manufacturing and material tolerances inherent in the stated meaning are given, and are intended to convey an understanding of the present invention. Accurate or absolute figures are used to help prevent exploitation by unscrupulous infringers of the disclosed disclosure.

The present invention relates to a polyester fiber for a binder formed of a sheath part and a core part, and relates to a polyester fiber in which the core part is formed of a general polyester resin and the sheath part is formed of a polyester resin for a binder.

Any general polyester resin forming the core part can be used, but it is preferable to use a polyethylene terephthalate (PET) resin made of terephthalic acid and ethylene glycol.

The polyester resin for a binder forming the sheath portion includes terephthalic acid or an ester-forming derivative thereof as an acid component and ethylene glycol as a diol component.

In general, polyester resin is a polymer resin produced by polymerization of terephthalic acid or its ester-forming derivatives as an acid component and ethylene glycol as a diol component. The benzene rings of terephthalic acid are regularly arranged to chemically reduce the flowability of the entire molecular chain. It does not behave easily by heat and has a high melting point.

The polyester resin for binders of the present invention uses terephthalic acid or its ester-forming derivatives and oxalic acid as acid components to reduce the number of benzene rings of terephthalic acid that reduces the flowability of molecular chains, thereby reducing the flowability of the entire molecular chain. increases and the melting point decreases.

In addition, the polyester resin for a binder of the present invention can improve sagging property when formed into a fiber, film, or molded article by increasing packing property due to a decrease in benzene rings in the molecular chain.

When the polyester resin for a binder of the present invention contains 30 mol% or more of the acid component of oxalic acid, the polymer becomes amorphous and has thermal properties similar to those of the conventional low-melting polyester resin for a binder containing isophthalic acid. It plays a role in improving tear properties when binding nonwoven fabric by improving elasticity due to flexible molecular chains present in the polymer backbone.

That is, in the polyester resin for a novel binder of the present invention, oxalic acid is included in the polyester main chain to increase the degree of freedom of the main chain and decrease the crystallinity of the resin, thereby controlling the softening point (Ts) and/or glass transition temperature (Tg). can This may exhibit the same effect as the case of using isophthalic acid (IPA) containing an asymmetric aromatic ring in order to lower the crystallinity of a conventional crystalline polyester resin.

The polyester resin for a binder of the present invention formed of the acid component as described above may preferably contain 30 to 60 mol% of oxalic acid in the acid component in order to improve low melting point characteristics and adhesion.

If the content of oxalic acid is too low, the melting point may not be lowered smoothly and may not be suitable for a binder. If the content of oxalic acid is too high, physical properties of the polyester resin may be deteriorated.

The oxalic acid containing 30 to 50 mol% of the acid component will be most preferable as the polyester resin for the binder.

As described above, the novel polyester resin for a binder according to the present invention has excellent physical properties such as a softening temperature of 100 ° C to 150 ° C and a glass transition temperature of 60 ° C to 90 ° C.

The polyester fiber for a novel binder of the present invention as described above can be thermally bonded at a low temperature in a range similar to the temperature applied to existing binder fibers, and has a glass transition temperature of 60 ° C. or higher, such as in a high-temperature atmosphere such as a product for interior automobiles. Even when durability and shape stability are required, strength is maintained, and even in nonwoven fabrics for molding, it has the advantage of preventing sagging under a high temperature atmosphere, and can be used for nonwoven fabrics for various purposes.

Hereinafter, an example of a method for producing a novel polyester fiber for a binder according to the present invention is shown, but the present invention is not limited to the examples.

Example 1 to 5

Terephthalic acid (TPA) and ethylene glycol (EG) were added to an ester reactor, and a conventional polymerization reaction was performed at 258° C. to prepare a polyethylene terephthalate polymer (PET oligomer) having a reaction rate of about 96%.

Oxalic acid was contained in the prepared polyethylene terephthalate (PET) as shown in Table 1, and a transesterification reaction was performed at 250±2° C. by adding a transesterification catalyst. Thereafter, a polycondensation reaction catalyst was added to the obtained reaction mixture, and a polycondensation reaction was performed while adjusting the final temperature and pressure in the reaction tank to 280 ± 2 ° C and 0.1 mmHg, respectively, to obtain a novel polyester resin for binder according to the present invention. manufactured.

The polyester fiber for binder of the present invention was prepared by using the polyester resin for binder prepared above as a sheath part and polyethylene terephthalate formed of terephthalic acid (TPA) and ethylene glycol (EG) as a core part.

A polyester fiber for a binder of the present invention was prepared through a general composite spinning process at a weight ratio of 50:50 between the sheath and the core.

Comparative Example 1

A polyester resin for a binder was prepared using terephthalic acid as an acid component and 2-methyl-1,3-propanediol (40 mol%) and ethylene glycol (60 mol%) as a diol component.

Composite fibers were prepared as in Example 1 using the polyester resin for the binder.

Comparative Example 2

A polyester resin for a binder was prepared using terephthalic acid (60 mol%) and isophthalic acid (40 mol%) as an acid component and ethylene glycol as a diol component.

Composite fibers were prepared as in Example 1 using the polyester resin for the binder.

division acid component Diol component Oxalic Acid (mol%) IPA (mole %) TPA (mole %) MPD (mole %) EG (mole %) Example 1 10 0 90 0 100 Example 2 20 0 80 0 100 Example 3 30 0 70 0 100 Example 4 40 0 60 0 100 Example 5 50 0 50 0 100 Comparative Example 1 0 0 100 40 60 Comparative Example 2 0 40 60 0 100

◈ Measurement of physical properties of Examples and Comparative Examples

The following physical properties of the polyester resin for binder and the polyester fiber for binder prepared in Examples and Comparative Examples were measured, and the results are shown in Tables 1 and 2.

(1) Measurement of softening point (or melting point) and glass transition temperature (Tg)

The glass transition temperature (Tg) of the copolymerized polyester resin was measured using a differential scanning calorimeter (Perkin Elmer, DSC-7), and the softening behavior was measured in TMA mode using a dynamic mechanical analyzer (DMA-7, Perkin Elmer). did

(2) Measurement of melt viscosity

After melting the polyester resin at the measurement temperature, the melt viscosity was measured using RDA-III of Rheometric Scientific. Specifically, when measured by setting Initial Frequency = 1.0 rad/s to Final Frequency = 500.0 rad/s under Frequency Sweep conditions at the set temperature, the value at 100 rad/s was calculated as the melt viscosity.

(3) Room temperature and high temperature adhesion measurement

The polyester fibers of Examples and Comparative Examples were heat-sealed to prepare a nonwoven fabric having a fixed density of 2 g/100 cm 2 , and the prepared nonwoven fabric was heated at 25±0.5° C. (room temperature) and 100±0.5° C. (high temperature) according to ASTM D1424. Adhesion was measured.

(4) High temperature shrinkage

After the polyester fiber for the binder is manufactured into short fibers, it is carded to produce a cylindrical shape. After applying 170 ℃ heat for 3 minutes, measure the reduced volume. In general, if it is less than 250 cm3, the shape stability is poor, and if it is more than 280 cm3, it can be evaluated as excellent.

(5) Measurement of compression hardness

After opening 5 g of polyester fiber and stacking it in a circular mold with a diameter of 10 cm to a height of 5 cm, it was thermally bonded at a set temperature for 90 seconds to prepare a cylindrical molded product. The manufactured molded article was compressed by 75% using Instron, and the compressive hardness was measured by measuring the load applied to compression. In this experiment, the compression hardness was measured by thermal bonding at 140 ° C, 150 ° C, and 160 ° C, respectively.

division Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 thermal
characteristic
(℃) softening temperature - - - 124.5 112.7 120 128 Tm 210.3 190.6 176.3 - - - - Tg 78.7 74.1 72.7 70.3 68.9 70.4 70.1 adhesion Adhesion at room temperature
(kgf) - - 63 77 81 75 64 high temperature adhesion
(kgf) - - 3.1 5.3 5.7 5.5 4.2 peel strength
(kgf-mm) 12.4 16.6 23.8 33.4 36.7 33.5 26.3 tear strength
(N/m) 2210 1875 1265 545 520 564 785 form
stability high temperature shrinkage
(cm) 313 308 298 288 283 285 290 compression
Hardness
(kgf) 140℃ 1.4 1.6 2.4 3.6 3.9 3.7 3.7 150℃ 2.7 2.9 3.7 5 5.6 4.7 4.9 160℃ 3.3 4.2 5.1 5.8 6 5.3 5.5

As shown in Table 2, the binder polyester resin contained in the binder polyester fibers of the present invention has crystallinity when oxalic acid is contained in an acid component in an amount of 10 to 30 mol%, but in Example 4 exceeding 30 mol%, In the case of 5, it can be seen that the melting point does not exist and has a non-crystallinity.

Examples 1 and 2 have a melting point of 190 to 210 ° C, which is lower than that of a general polyester resin, and can be used as a polyester resin for a binder for various purposes, and Examples 3 to 5 are a polyester resin for a binder at a lower temperature. will be available

As in Examples 4 and 5, when 40 to 50 mol% of oxalic acid is contained in the acid component, it has similar or better room temperature and high temperature adhesive strength to those of Comparative Examples 1 and 2, which are conventional polyester fibers for binders, and has peel strength and It is also excellent in compression hardness, and it can be seen that the polyester fiber for binder of the present invention has excellent physical properties.

In addition, it can be seen that Examples 1 to 5 and Comparative Examples 1 and 2 all have good high-temperature shrinkage of 260 cm 3 or more.

As described above, the novel polyester fiber for binder according to the present invention can be used for various purposes with properties similar to or superior in physical properties to polyester fibers using conventionally used polyester resins for binders.

Claims (5)

In the polyester fiber for binder formed of the sheath part and the core part,
The core part is formed of a general polyester resin,
The cis portion is formed of a polyester resin for a binder containing terephthalic acid or an ester-forming derivative thereof and oxalic acid as an acid component and ethylene glycol as a diol component,
Oxalic acid of the polyester resin for the binder is a polyester fiber for a binder, characterized in that it has an amorphous nature by containing more than 30 mol% to 60 mol% of the acid component. According to claim 1,
Oxalic acid of the polyester resin for the binder is a polyester fiber for a binder, characterized in that it contains more than 30 mol% to 50 mol% of the acid component. According to claim 1,
The polyester resin for the binder is a polyester fiber for a binder, characterized in that the softening temperature is 100 ℃ ~ 150 ℃. According to claim 1,
The polyester resin for the binder is a polyester fiber for a binder, characterized in that the glass transition temperature is 60 ℃ to 90 ℃. A nonwoven fabric comprising the polyester fiber for a binder according to any one of claims 1 to 4.